Steering wander

[ecohorsie]

So after lots of research online I still can't find resolution. Seems like many people experience this on S550s
My car is a 2016 GT vert with full bolt on suspension: Steeda- progressive springs, proaction shocks struts , Steeda front control arms for lowered cars, Eibach sway bars, rear IRS lockout , BMR vert links , BMR k brace , MM camber plates, spherical toe link bearing ,
Bump steer kit , PP1 wheels with Michelin ps4s
Swapped all stuff from my ecoboost coupe.
The eco drove great but felt a bit stiffer. The faster I drove the better it felt. My GT is different. steering feels like it wanders a bit which eco didn't do. Pretty sure its not tramlining or bump steer as it happens going straight on relatively smooth highway. Car was aligned to recommended Steeda performance specs.
Steering is good in turns and tight otherwise.
Any ideas?

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[NightmareMoon]

Pics of alignment sheet?

what type of tires and tire condition?

 

[ecohorsie]

Pp1 wheels with Michelin PS4S with about 9000 miles on them. They were off my eco with same Steeda stuff My caster is off on right side and that could contribute but it seems like a lot of people have same complaint with even caster.
I will be addressing the alignment soon.

 

[NightmareMoon]

IDK how your caster got like that. Did you hit something? Its normally not something that moves.

Nothing else really sticks out.

 

[ecohorsie]

Yes car was in accident on right side. Wheel was broken. Probably shifted subframe. So this is first place to start but I found a lot of similar complaints even with good alignment online.
I do have the stock wheels with pirellis that I'll try as well to rule out tires.

 

[Dana Pants]

Looks like you have front toe out… try a hair toe in.

 

[cmxPPL219]

The caster is the most likely culprit causing those handling issues you're facing. The caster should have relatively little adjustment on these cars, and should be something in the 7* region.

It's off quite a bit, and based on the info you mentioned about the hit, this could have bent something that alignment cannot compensate for.

Toe should also be corrected, but the caster is way off.

 

[TeeLew]

Caster in the front needs addressed as does the cross-camber in the rear.

 

[NightmareMoon]

Looks like you have front toe out… try a hair toe in.

I think positive toe is toe in

 

[ecohorsie]

So so far I have determined that my BMR k brace was not allowing me to torque the rear suspension link on front suspension. I removed it and torqued links proper and most of the bad stuff is gone. I'm sure once I figure out the alignment it'll be pretty good. I'll be doing A Torsen 3.73 rear diff so will wait till I get that in before heading back to alignment shop.

 

[thompsje]

So so far I have determined that my BMR k brace was not allowing me to torque the rear suspension link on front suspension. I removed it and torqued links proper and most of the bad stuff is gone. I'm sure once I figure out the alignment it'll be pretty good. I'll be doing A Torsen 3.73 rear diff so will wait till I get that in before heading back to alignment shop.

Can you elaborate on how the BMR brace isn't letting you torque the link mounts? I've been waffling on replacing the Steeda for a little more ground clearance, but interested in the BMR issue. Is it a clearance problem on the bushing mount points?

 

[ecohorsie]

My car was hit on right side so maybe I have a tweaked aft control arm mounting flange. This brace was on my eco with no problems so I wouldn't not get it because of my issues. The BMR piece is nice otherwise.

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